Dynamic Reconstruction of Ni/In2O3/ZrO2 Catalyst in Reverse Water-Gas Conversion Reaction.

Abstract

The reconfiguration of catalysts in situ will obviously affect their catalytic performance, while the evolution process and the mechanism of reaction process remain unclear. Herein, a series of ternary Ni/In₂O₃/ZrO₂ catalysts is prepared by the two-step method. In the reaction atmosphere (CO₂/H₂), In₂O₃ particles are highly dispersed on the carrier ZrO₂, and are partially reduced to form InO_x layers. Moreover, In₂O₃ tends to migrate near Ni species, forming the NiInO_x complex structure decorated by InO_x layers. It is demonstrated that indium oxide serves as the main active site in the reverse water-gas conversion reaction, and Ni species function as an auxiliary agent to generate the strong metal-support interaction effect with indium oxide, facilitate the formation of the key intermediates HCOO* and CO*, and further enhance the CO yield. Ab initio molecular dynamics and density functional theory calculations confirm that the In₂O₃ clusters have undergone dynamic structural reconstruction on the ZrO₂ support driven by temperature, and In₂O₃ serves as the preferential adsorption site for CO₂.